nptl: Add pthread_attr_setsigmask_np, pthread_attr_getsigmask_np

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>

1 files changed, 204 insertions, 0 deletions

diff --git a/nptl/tst-pthread-attr-sigmask.c b/nptl/tst-pthread-attr-sigmask.c
new file mode 100644
index 0000000..8f854d8
--- /dev/null
+++ b/nptl/tst-pthread-attr-sigmask.c
@@ -0,0 +1,204 @@
+/* Tests for pthread_attr_setsigmask_np, pthread_attr_getsigmask_np.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+/* This thread uses different masked status for SIGUSR1, SIGUSR2,
+   SIGHUP to determine if signal masks are applied to new threads as
+   expected.  */
+
+#include <signal.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <support/check.h>
+#include <support/xsignal.h>
+#include <support/xthread.h>
+#include <threads.h>
+
+typedef bool signals[_NSIG];
+
+static const char *
+masked_or_unmasked (bool masked)
+{
+  if (masked)
+    return "masked";
+  else
+    return "unmasked";
+}
+
+/* Report an error if ACTUAL_MASK does not match EXPECTED_MASK.
+   CONTEXT is used in error messages.  */
+static void
+check_sigmask (const char *context, signals expected_mask,
+               const sigset_t *actual_mask)
+{
+  for (int sig = 1; sig < _NSIG; ++sig)
+    if (sigismember (actual_mask, sig) != expected_mask[sig])
+      {
+        support_record_failure ();
+        printf ("error: %s: signal %d should be %s, but is %s\n",
+                context, sig,
+                masked_or_unmasked (sigismember (actual_mask, sig)),
+                masked_or_unmasked (expected_mask[sig]));
+      }
+}
+
+/* Report an error if the current thread signal mask does not match
+   EXPECTED_MASK.  CONTEXT is used in error messages.  */
+static void
+check_current_sigmask (const char *context, signals expected_mask)
+{
+  sigset_t actual_mask;
+  xpthread_sigmask (SIG_SETMASK, NULL, &actual_mask);
+  check_sigmask (context, expected_mask, &actual_mask);
+}
+
+/* Thread start routine which checks the current thread signal mask
+   against CLOSURE.  */
+static void *
+check_sigmask_thread_function (void *closure)
+{
+  check_current_sigmask ("on thread", closure);
+  return NULL;
+}
+
+/* Same for C11 threads.  */
+static int
+check_sigmask_thread_function_c11 (void *closure)
+{
+  check_current_sigmask ("on C11 thread", closure);
+  return 0;
+}
+
+/* Launch a POSIX thread with ATTR (which can be NULL) and check that
+   it has the expected signal mask.  */
+static void
+check_posix_thread (pthread_attr_t *attr, signals expected_mask)
+{
+  xpthread_join (xpthread_create (attr, check_sigmask_thread_function,
+                                  expected_mask));
+}
+
+/* Launch a C11 thread and check that it has the expected signal
+   mask.  */
+static void
+check_c11_thread (signals expected_mask)
+{
+  thrd_t thr;
+  TEST_VERIFY_EXIT (thrd_create (&thr, check_sigmask_thread_function_c11,
+                                 expected_mask) == thrd_success);
+  TEST_VERIFY_EXIT (thrd_join (thr, NULL) == thrd_success);
+}
+
+static int
+do_test (void)
+{
+  check_current_sigmask ("initial mask", (signals) { false, });
+  check_posix_thread (NULL, (signals) { false, });
+  check_c11_thread ((signals) { false, });
+
+  sigset_t set;
+  sigemptyset (&set);
+  sigaddset (&set, SIGUSR1);
+  xpthread_sigmask (SIG_SETMASK, &set, NULL);
+  check_current_sigmask ("SIGUSR1 masked", (signals) { [SIGUSR1] = true, });
+  /* The signal mask is inherited by the new thread.  */
+  check_posix_thread (NULL, (signals) { [SIGUSR1] = true, });
+  check_c11_thread ((signals) { [SIGUSR1] = true, });
+
+  pthread_attr_t attr;
+  xpthread_attr_init (&attr);
+  TEST_COMPARE (pthread_attr_getsigmask_np (&attr, &set),
+                PTHREAD_ATTR_NO_SIGMASK_NP);
+  /* By default, the signal mask is inherited (even with an explicit
+     thread attribute).  */
+  check_posix_thread (&attr, (signals) { [SIGUSR1] = true, });
+
+  /* Check that pthread_attr_getsigmask_np can obtain the signal
+     mask.  */
+  sigemptyset (&set);
+  sigaddset (&set, SIGUSR2);
+  TEST_COMPARE (pthread_attr_setsigmask_np (&attr, &set), 0);
+  sigemptyset (&set);
+  TEST_COMPARE (pthread_attr_getsigmask_np (&attr, &set), 0);
+  check_sigmask ("pthread_attr_getsigmask_np", (signals) { [SIGUSR2] = true, },
+                 &set);
+
+  /* Check that a thread is launched with the configured signal
+     mask.  */
+  check_current_sigmask ("SIGUSR1 masked", (signals) { [SIGUSR1] = true, });
+  check_posix_thread (&attr, (signals) { [SIGUSR2] = true, });
+  check_current_sigmask ("SIGUSR1 masked", (signals) { [SIGUSR1] = true, });
+
+  /* But C11 threads remain at inheritance.  */
+  check_c11_thread ((signals) { [SIGUSR1] = true, });
+
+  /* Check that filling the original signal set does not affect thread
+     creation.  */
+  sigfillset (&set);
+  check_posix_thread (&attr, (signals) { [SIGUSR2] = true, });
+
+  /* Check that clearing the signal in the attribute restores
+     inheritance.  */
+  TEST_COMPARE (pthread_attr_setsigmask_np (&attr, NULL), 0);
+  TEST_COMPARE (pthread_attr_getsigmask_np (&attr, &set),
+                PTHREAD_ATTR_NO_SIGMASK_NP);
+  check_posix_thread (&attr, (signals) { [SIGUSR1] = true, });
+
+  /* Mask SIGHUP via the default thread attribute.  */
+  sigemptyset (&set);
+  sigaddset (&set, SIGHUP);
+  TEST_COMPARE (pthread_attr_setsigmask_np (&attr, &set), 0);
+  TEST_COMPARE (pthread_setattr_default_np (&attr), 0);
+
+  /* Check that the mask was applied to the default attribute.  */
+  xpthread_attr_destroy (&attr);
+  TEST_COMPARE (pthread_getattr_default_np (&attr), 0);
+  sigaddset (&set, SIGHUP);
+  TEST_COMPARE (pthread_attr_getsigmask_np (&attr, &set), 0);
+  check_sigmask ("default attribute", (signals) { [SIGHUP] = true, }, &set);
+  xpthread_attr_destroy (&attr);
+
+  /* Check that the default attribute is applied.  */
+  check_posix_thread (NULL, (signals) { [SIGHUP] = true, });
+  check_c11_thread ((signals) { [SIGHUP] = true, });
+
+  /* An explicit attribute with no signal mask triggers inheritance
+     even if the default has been changed.  */
+  xpthread_attr_init (&attr);
+  check_posix_thread (&attr, (signals) { [SIGUSR1] = true, });
+
+  /* Explicitly setting the signal mask affects the new thread even
+     with a default attribute.  */
+  sigemptyset (&set);
+  sigaddset (&set, SIGUSR2);
+  TEST_COMPARE (pthread_attr_setsigmask_np (&attr, &set), 0);
+  check_posix_thread (&attr, (signals) { [SIGUSR2] = true, });
+
+  /* Resetting the default attribute brings back the old inheritance
+     behavior.  */
+  xpthread_attr_destroy (&attr);
+  xpthread_attr_init (&attr);
+  TEST_COMPARE (pthread_setattr_default_np (&attr), 0);
+  xpthread_attr_destroy (&attr);
+  check_posix_thread (NULL, (signals) { [SIGUSR1] = true, });
+  check_c11_thread ((signals) { [SIGUSR1] = true, });
+
+  return 0;
+}
+
+#include <support/test-driver.c>